The present invention relates to a cryostatic collection device capable of collecting and storing a plurality of samples isolated in a matrix for presentation to a beam of light or other electromagnetic radiation for absorption spectroscopy. It is particularly applicable as an interfacial component within a system incorporating gas chromatography and infrared spectroscopy for the analysis of gas samples including a number of components.
The device may also have application in systems employing other characterizing electromagnetic radiation including not only infrared light but visible light and ultraviolet light. This present device may also be useful in analytical systems that rely on luminescence, phosphorescence, fluorescence or on laser interrogation, e.g. the laser raman matrix-isolation spectroscopy. For purposes of this application the term "light", unless otherwise specified, is intended to contemplate this broader scope of applications.
Gas chromatographic separations have been useful fundamental tools of chemical research and analysis for some time. Their usefulness is greatly enhanced when the separated components can be conveniently and promptly analyzed. The matrix-isolation technique for presenting samples for spectroscopic examination is also of considerable value in obtaining precise analysis of samples including specific structural information about molecular construction through high-resolution infrared analyses. Previously no satisfactory system has combined these two highly useful techniques.
In matrix-isolation spectroscopy, a particular and distinct sample material is entrapped within a frozen matrix of an inert substance such as argon or krypton gas. This technique permits the retention of the sample in a neutral and noncontaminating matrix material over an extended period of time. Consequently extremely high resolution can be obtained in spectroscopic and other optical types of analyses.
Gas chromatographic systems are employed to separate collected samples into particular components or bands to permit their identification. These type separations are based on the retention of individual gas components on an absorptive surface. In some of the previous systems, components have been collected manually in liquid and gas microcells at ambient or elevated temperature for subsequent analyses. In other systems, a stop-flow mode of operation is incorporated into the chromatographic unit such that gas flow is retarded while infrared spectra of components are taken. In this type system, only a short time is available for analysis and none of the components are retained for duplication of test results. In another commercially available system, gas chromatogram discharge passes through a light pipe for "on the fly" infrared spectroscopy with such as a fourier-transform mode of operation. These existing systems for gas analyses exhibit limited observation time and consequently suffer in both precision and resolution.